It is the purpose of this study to determine the nature and the biochemical changes, as well as immunological properties, in the secretory and plasma membrane glycoproteins, which occur in the epithelial cells of the large intestine, as a result of chemically induced carcinogenesis. This will be followed by later studies with human colons. BIBLIOGRAPHIC REFERENCES: W. Pigman, Comparative Biochemistry of Mucins. Abstract, Third Inter. Symposium of Glycoconjugates: Functions in Animals, Brighton, England, 1975. A. Herp and V. Perret, Preparation and Studies of Epithelial Cells of the Rat Large Intestine. Abstract, Tenth Inter. Congress Biochem., Hamburg, Germany, 1976.